silverstripe/silverstripe-framework — pull request #2603 by chillu (2013-10-24 12:52:11+00:00)
Title: Default UploadField to replace files

Honours the $overwriteWarning setting, rather than warning
about overwritten files, and when that warning is acknowledged by the user,
create a new file instead. We need to set this as close to
the Upload->load() call as possible, since it depends
on non-deterministic config state.